FAULL: DEVELOPMENT OF ASCUS. 
99 
Origin of the Ascus. 
According to the researches of Dangeard (’94) and Harper (:00) 
the ascus originates from the cell next to the terminal one. After 
an examination of thirty-six species from which it is possible to deter¬ 
mine this matter, it has been found that such is invariably the case 
in but eleven of them. 
Maire (: 03) and Guilliermond (: 03a ) have recently reported devia¬ 
tions from the conventional type in Aleuria cerea (?), and Galac- 
tinia succosa. In the former the ascus arises from a penultimate 
cell in which there are two nuclei, but the terminal cell likewise con¬ 
tains two nuclei. In Galactinia succosci the end of the hypha is not 
hooked, the last two or three cells enclose two nuclei each, and the 
ascus springs from the terminal cell. 
The most frequent deviation from what has been taken as the con¬ 
ventional type is that represented in figure 74 (pi. 11) for Genea 
hispidula. In this case the ascus grows out from a curved terminal 
cell. It is quite probable that the only departure from the type is 
the lack of the cross wall that cuts oil a uninucleated cell at the tip 
of the hypha. Other forms that resemble Genea hispidula in this 
respect are Podospora anserina , P. setosa , Sordaria jimicola , IS. 
humana , Geoglossum ophioglossoides , G. hirsutum , Geoglossum sp., 
Verpct conica , Gyromitra sphaerospora , Leptoglossum luteum , 
Leptoglossum sp., Mitrula phalloides, Leotia lubrica , L. chloro- 
cephala , Phyllachora graminis , and Piscina venosa. In some of 
these the missing partition is found to be present exceptionally. 
Of all the forms examined, Verpa bohemica exhibits the greatest 
variability. It has been hitherto stated that asci spring from the 
penultimate cell and that the terminal one develops no further. 
Both of these statements may be incorrect as far as Verpa bohe¬ 
mica is concerned. Thus, asci sometimes occur as represented in 
figure 79 (pi. 11) as outgrowths of a terminal cell. In the case fig¬ 
ured there is a second outgrowth which is perhaps of later origin 
than the ascus. Again, the ascus may be found to grow out from 
the second, third, or even fourth cell from the end (pi. 11, figs. 71, 
72, 75, 77). It remains to be determined yet whether the terminal 
cell underwent divisions after the budding out of the ascus, or 
whether the ascus may grow out of the third or fourth cell as it 
sometimes does from either the first or the second. In Anixia 
i 
